Look up "interference fit"...

The GSP axle might have been made a tiny tiny bigger than spec,
you are talking about delta difference (in diameter) of ~ 0.03 mm or so.
This is enough to force the axle in (during installation)...but when it comes
to removal, bc it is on too tight, the bearing comes out with it.

Use only GKN...
Or a good used BMW axle (made by GKN).

Seal: Corteco.

I wrote a full DIY on bimmerfest E53 forum in 2025...

PS: when it comes to axle, seals, I only use original mfg bc this stuff is down
to 0.03 mm etc. And this is the job I don't want to do twice.

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1998 E39 528i 5sp MT
2006 E53 X5 3.0 6sp MT